There was a video I've seen someone, a year ago, setup a 'pre-heater' for their home heating system with a mining rig, so that the home heater doesn't have to use nearly as much fuel/electricity to warm the home. I forget how efficient it was, but the summary was that the net decrease in cost to run the heater was observable but not significant enough to justify everyone doing so.
That sounds freaking awesome. Do you know how to find it? I found a company called Qarnot that's offering products along those lines but they're probably extremely expensive. A home project would be ideal.
The premise was to only operate the miner in cold months, when the outside air could easily cool the system. I didn't fully re-watch this video but it does give a good setup and explanation for it.
